public class D7 {
    private int a;
    public String b = "Hello";
    public static int count = 0;
    public static void main(String[] args) {
        D7 d = new D7();
        d.a = 10;
        System.out.println("a: " + d.a);
        d.b = "fucker fucker";
        System.out.println("b: " + d.b);

        D7Son son = new D7Son();
        System.out.println(son.returnFather_var_b());
        System.out.println(son.returnFather_var_count());
    }

    public D7() {// when new a instance, count will add 1
        ++count;
    }

}

class D7Son extends D7 {
    public String returnFather_var_b() {
        return super.b;
    }

    // public int returnFather_var_a() {
    // // can not access to private field
    // }
    @SuppressWarnings("all")
    public int returnFather_var_count() {
        return super.count;
    }
}
